Kashikomarimashita, Destiny
Sweet and heart-warming. An omega son of a wealthy, well-connected alpha family is left alone with only his beta bulter after his parents die and is taken in by a family that was friends with his. The son of the head of the family is his soulmate but has struggled against acknowledging it since they were children because he's sick of having no choices in life. But one day the omega goes into heat and they are pulled together anyway. This manga also goes into the personal life of the beta butler and his romance with a fellow butler who's an alpha. That's also super sweet, maybe even more so. ETA: This manga turned out to be way more about the butler couple! It seems rare to find so many good feels in an omegaverse story but there you have it. This is probably THE BEST omegaverse manga.
Oh, My Young Master!
I like the art style and the plot is interesting enough. Master and butler are kicked out of their home by the father, who wants the boy to learn a lesson and be able to support himself. They go through tough times, living homeless and getting rejected from job interviews until one day they save a woman who wants to make them into hosts.
Butler Game
Hmmm, this was ok but nothing I'm like super enthusiastic about. The butler comes off pretty creepy (with the whole grooming him since he was a kid stuff) and the master as a typical powerless/weak uke.
Shitsuji wa Oose no Mama ni
A bunch of pretty decent one shots. 1-2) butler x master 3)student x tutor 4)older family friend x student 5)cat-boys 6)friends and new stepbrothers 7)vampire x boy he raised
Kyouju to Shitsuji no Shizuka na Seikatsu